Let me tell you Nigel I honestly mean it when I say your input is appreciated. I am trying to continuously profit from whatever is coming down the pike and your data will be used. What seems to be important is VARS (the phase angle which pulls amp wave & volt wave together for an elec motor to produce torque). As I would imagine you know - that grid you speak of needs mechanical generators that produce those VARS to stay stable. My claims that I had made were based on the effect my set up has on that (none). I may have just broadcasted that poorly which lead to you calling it out. No harm though as we are on the same track.
We think when & if solar & wind displace VAR producing big steam gens it can eventually destabilize that grid. But those chances are remote. You know that we need big generators for inertia but as renewables (funded by government) force big generators to bankruptcy (then shut down) the grid will be less stable. My pals run their hydro units at zero power output just to produce VARS strictly making up for the less than optimal renewable sources. Of course those renewables don't produce any spinning reserve (sorta what you spoke to earlier). So now grid operators are having to pay for thermal units to run at less than rating to maintain some spinning reserve. Here is the big thing... It could all work well (we think) together if guys like you (engineers) figured out the economics between dispatching the two - rather than the accountants & politicians.
Stay on it. We need you to make it work.
I've done a little homework since this thread just to make sure I understood the significance of power factor (at least at a high level). So I will summarize what I think is going on building on the basics of what you laid out. Still do not have the full picture on power factor workings and effects though. So for anyone interested...
Both inductive and capacitive loads impact the reactive power or the power factor. Since AC power is a sine wave, the voltage and current also follow a sine wave, and when you get a shift in those two sign waves (angle between them) you get a real power vector and a reactive power vector (imaginary vector if computing using the complex plane). The ratio of real to reactive power is called power factor.
When you get a shift in the phase of the volts and the current you actually get less work and power (the out of phase current does no work) for the current you are carrying. Since inductive loads like induction motors require a fixed amount of power to run, they will require more current when the power factor is less than 1, because power is volts times amps. The further the shift, proportionately more current. The increased current requires oversizing all electrical equipment to carry the excess current, plus transmission losses increase. If you loose control of the power factor, you are going fry a bunch of stuff.
Synchronous generators are designed to control power factor, and can have a leading or lagging power factor, so this capability helps stabilize the voltage and current to ensure that the grid does not have an over current situation. Large consumers with inductive loads can use capacitor banks or auto-transformers to help correct the power factor for the inductive load. This is common practice for industrial consumers.
Inverters can't compensate as you pointed out, plus they also have to be oversized to handle the extra current for a given power factor.
Typical grid power factor is around 0.9, I believe, and synchronous generators are required by grid code to maintain the specified power factor.
The one thing, other than increased transmission losses, the actual power required to drive the turbines does not change due to power factor.
